Return empty change set

api/s5_pipes.py

@@ -11,9 +11,9 @@ PIPE_STATUS_CV = 'cv'
 
 def add_pipe(name: str, id: str, node1: str, node2: str, length: float = 0, diameter: float = 0, roughness: float = 0, minor_loss: float = 0, status: str = PIPE_STATUS_OPEN) -> ChangeSet:
     if not is_node(name, node1):
-        return
+        return ChangeSet()
     if not is_node(name, node2):
-        return
+        return ChangeSet()
 
     sql = f"insert into pipes (id, node1, node2, length, diameter, roughness, minor_loss, status) values ('{id}', '{node1}', '{node2}', {length}, {diameter}, {roughness}, {minor_loss}, '{status}');"
     undo_sql = f'delete from pipes where id = "{id}";'
@@ -26,11 +26,11 @@ def _get_pipe(name: str, id: str) -> Row | None:
 
 def delete_pipe(name: str, id: str) -> ChangeSet:
     if not is_pipe(name, id):
-        return
+        return ChangeSet()
 
     row = _get_pipe(name, id)
     if row == None:
-        return
+        return ChangeSet()
 
     node1, node2, length, diameter, roughness, minor_loss, status = row['node1'], row['node2'], row['length'], row['diameter'], row['roughness'], row['minor_loss'], row['status']
 
@@ -77,25 +77,25 @@ def get_pipe_status(name: str, id: str) -> str | None:
 
 def _set_pipe(name: str, id: str, key: str, key_type: str, value: str, optional: bool = False) -> ChangeSet:
     if not is_pipe(name, id):
-        return
+        return ChangeSet()
 
     row = _get_pipe(name, id)
     if row == None:
-        return
+        return ChangeSet()
 
     return utility.update(name, PIPE, 'pipes', 'id', id, key, key_type, row[key], value, optional)
 
 
 def set_pipe_node1(name: str, id: str, node1: str) -> ChangeSet:
     if not is_node(name, node1):
-        return
+        return ChangeSet()
 
     return _set_pipe(name, id, 'node1', 'str', str(node1))
 
 
 def set_pipe_node2(name: str, id: str, node2: str) -> ChangeSet:
     if not is_node(name, node2):
-        return
+        return ChangeSet()
 
     return _set_pipe(name, id, 'node2', 'str', str(node2))